Several reports have revealed the vital role that probiotics play in fish growth and health.However,few works are available for host gut-derived probiotics on the growth,immunity,and gut microbiota of fish,especially ...Several reports have revealed the vital role that probiotics play in fish growth and health.However,few works are available for host gut-derived probiotics on the growth,immunity,and gut microbiota of fish,especially in hybrid grouper (♀Epinephelus fuscoguttatus×♂Epinephelus lanceolatus) due to their isolation difficulty and functional verification.This study aimed at assessing 3 host gut-derived Bacillus species?effects on the growth,immune and antioxidant-biochemical responses,haematological parameters,intestinal morphology,immune-related gene expression,gut microbiota,and disease resistance against Vibrio harveyi in hybrid grouper.A total of 480 hybrid grouper (initial weight=9.03±0.02 g) were randomly allotted into 4 groups,namely,the group fed a basal diet without probiotic inclusion (control,B0),the group fed the basal diet with Bacillus velezensis GPSAK4 (BV),the group fed the basal diet with Bacillus subtilis GPSAK9 (BS),and the group fed the basal diet with Bacillus tequilensis GPSAK2 (BT) strains at 1.0×10^(9)CFU/g.After a 6-week feeding trial,the results revealed significant improvements (P<0.05) in the growth performance,whole fish-body proximate composition,blood haematological parameters,serum,liver,and intestinal biochemical indexes,intestinal morphology,and protection against V.harveyi pathogen in the probiotic-treated groups compared with the untreated.Additionally,the expressions of intestinal tight junction genes (occludin and ZO1),pro-and anti-inflammatory genes,including IL1β,IL6,IL8,TNFa,MyD88,IL10,and TGFβ,were upregulated (P<0.05) after Bacillus species administration.Host gut-derived Bacillus supplementation shaped the gut microbiota by significantly increasing (P<0.05) the relative abundance of Proteobacteria,Bacteroidetes,Actinobacteria (except the BS group),Acidobacteria(except the BT group),Cyanobacteria (except the BV and BT groups),and Verrucomicrobia phyla,as well as known beneficial genera (Romboutsia,Turicibacter,Epulopiscium,Clostridium_sensu_stricto 1 and 13,Lactobacillus,and Bacillus),but significantly decreased (P<0.05) the abundance of Firmicutes,Chloroflexi,and Fusobacteria phyla,and purported pathogenic genera (Staphylococcus and Photobacterium) compared with the control group.Collectively,the results suggest that B.velezensis GPSAK4,B.subtilis GPSAK9(especially this strain),B.tequilensis GPSAK2 dietary supplementation at 1.0×10^(9)CFU/g has positive effects on the intestinal health of hybrid grouper via microbial composition modulation,thus enhancing the assimilation and absorption of nutrients to boost fish growth,immunity,and disease resistance.展开更多
Iso-nitrogenous and iso-lipidic diets containing 0%,3%,6%,9%,and 12%hydrolyzed porcine mucosa(namely,HPM0,HPM3,HPM6,HPM9,and HPM12)were prepared to evaluate their effects on the growth performance,muscle nutrition com...Iso-nitrogenous and iso-lipidic diets containing 0%,3%,6%,9%,and 12%hydrolyzed porcine mucosa(namely,HPM0,HPM3,HPM6,HPM9,and HPM12)were prepared to evaluate their effects on the growth performance,muscle nutrition composition,texture property,and gene expression related to muscle growth of hybrid groupers(Epinephelus fuscoguttatus\Epinephelus lanceolatus_).Groupers were fed to apparent satiation at 08:00 and 16:00 every day for a total of 56 days.It was found that the weight gain percentage in the HPM0,HPM3,and HPM6 groups did not differ(P>0.05).The cooking loss and drip loss of the dorsal muscle in the HPM3 group were lower than those in the HPM6 and HPM9 groups(P<0.05).The hardness and chewiness of the dorsal muscle in the HPM3 group were higher than those in the HPM0,HPM9,and HPM12 groups(P<0.05).The gumminess in the HPM3 group was higher than that in the HPM9 and HPM12 groups(P<0.05).The total essential amino acid content of the dorsal muscle in the HPM12 group was higher than that in the HPM0 group(P<0.05).The contents of total n-3 polyunsaturated fatty acid and total n-3 highly unsaturated fatty acid,as well as the ratio of n-3/n-6 polyunsaturated fatty acid in the dorsal muscle was higher in the HPM0 group than in all other groups(P<0.05).The relative expressions of gene myogenic factor 5,myocyte enhancer factor 2c,myocyte enhancer factor 2a,myosin heavy chain,transforming growth factor-beta 1(TGF-b1),and follistatin(FST)were the highest in the dorsal muscle of the HPM3 group.The results indicated that the growth performance of hybrid grouper fed a diet with 6%HPM and 27%fish meal was as good as that of the HPM0 group.When fish ingested a diet containing 3%HPM,the expression of genes TGF-β1 and FST involved in muscle growth were upregulated,and then the muscle quality related to hardness and chewiness were improved.An appropriate amount of HPM could be better used in grouper feed.展开更多
基金supported financially by the General Program of Natural Science Foundation of Guangdong Province(2021A1515011165)the Department of Education of Guangdong Province (2021ZDZX4005)+2 种基金the National Natural Science Foundation of China (31972808)the Research and Demonstration of Precision Functional Compound Feed Technology of Major Cultured Fishes and Shrimps in South China (2021B0202050002)the China Agriculture Research System of MOF and MARA (CARS-47)。
文摘Several reports have revealed the vital role that probiotics play in fish growth and health.However,few works are available for host gut-derived probiotics on the growth,immunity,and gut microbiota of fish,especially in hybrid grouper (♀Epinephelus fuscoguttatus×♂Epinephelus lanceolatus) due to their isolation difficulty and functional verification.This study aimed at assessing 3 host gut-derived Bacillus species?effects on the growth,immune and antioxidant-biochemical responses,haematological parameters,intestinal morphology,immune-related gene expression,gut microbiota,and disease resistance against Vibrio harveyi in hybrid grouper.A total of 480 hybrid grouper (initial weight=9.03±0.02 g) were randomly allotted into 4 groups,namely,the group fed a basal diet without probiotic inclusion (control,B0),the group fed the basal diet with Bacillus velezensis GPSAK4 (BV),the group fed the basal diet with Bacillus subtilis GPSAK9 (BS),and the group fed the basal diet with Bacillus tequilensis GPSAK2 (BT) strains at 1.0×10^(9)CFU/g.After a 6-week feeding trial,the results revealed significant improvements (P<0.05) in the growth performance,whole fish-body proximate composition,blood haematological parameters,serum,liver,and intestinal biochemical indexes,intestinal morphology,and protection against V.harveyi pathogen in the probiotic-treated groups compared with the untreated.Additionally,the expressions of intestinal tight junction genes (occludin and ZO1),pro-and anti-inflammatory genes,including IL1β,IL6,IL8,TNFa,MyD88,IL10,and TGFβ,were upregulated (P<0.05) after Bacillus species administration.Host gut-derived Bacillus supplementation shaped the gut microbiota by significantly increasing (P<0.05) the relative abundance of Proteobacteria,Bacteroidetes,Actinobacteria (except the BS group),Acidobacteria(except the BT group),Cyanobacteria (except the BV and BT groups),and Verrucomicrobia phyla,as well as known beneficial genera (Romboutsia,Turicibacter,Epulopiscium,Clostridium_sensu_stricto 1 and 13,Lactobacillus,and Bacillus),but significantly decreased (P<0.05) the abundance of Firmicutes,Chloroflexi,and Fusobacteria phyla,and purported pathogenic genera (Staphylococcus and Photobacterium) compared with the control group.Collectively,the results suggest that B.velezensis GPSAK4,B.subtilis GPSAK9(especially this strain),B.tequilensis GPSAK2 dietary supplementation at 1.0×10^(9)CFU/g has positive effects on the intestinal health of hybrid grouper via microbial composition modulation,thus enhancing the assimilation and absorption of nutrients to boost fish growth,immunity,and disease resistance.
基金This study was supported by the Fund of The National Key R&D Program of China(2019YFD0900200)Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang)(No.ZJW2019-06)+1 种基金China Agricultural Research System(CARS-47)Guangdong Modern Agriculture Research System-Innovation Team(2020KJ150).
文摘Iso-nitrogenous and iso-lipidic diets containing 0%,3%,6%,9%,and 12%hydrolyzed porcine mucosa(namely,HPM0,HPM3,HPM6,HPM9,and HPM12)were prepared to evaluate their effects on the growth performance,muscle nutrition composition,texture property,and gene expression related to muscle growth of hybrid groupers(Epinephelus fuscoguttatus\Epinephelus lanceolatus_).Groupers were fed to apparent satiation at 08:00 and 16:00 every day for a total of 56 days.It was found that the weight gain percentage in the HPM0,HPM3,and HPM6 groups did not differ(P>0.05).The cooking loss and drip loss of the dorsal muscle in the HPM3 group were lower than those in the HPM6 and HPM9 groups(P<0.05).The hardness and chewiness of the dorsal muscle in the HPM3 group were higher than those in the HPM0,HPM9,and HPM12 groups(P<0.05).The gumminess in the HPM3 group was higher than that in the HPM9 and HPM12 groups(P<0.05).The total essential amino acid content of the dorsal muscle in the HPM12 group was higher than that in the HPM0 group(P<0.05).The contents of total n-3 polyunsaturated fatty acid and total n-3 highly unsaturated fatty acid,as well as the ratio of n-3/n-6 polyunsaturated fatty acid in the dorsal muscle was higher in the HPM0 group than in all other groups(P<0.05).The relative expressions of gene myogenic factor 5,myocyte enhancer factor 2c,myocyte enhancer factor 2a,myosin heavy chain,transforming growth factor-beta 1(TGF-b1),and follistatin(FST)were the highest in the dorsal muscle of the HPM3 group.The results indicated that the growth performance of hybrid grouper fed a diet with 6%HPM and 27%fish meal was as good as that of the HPM0 group.When fish ingested a diet containing 3%HPM,the expression of genes TGF-β1 and FST involved in muscle growth were upregulated,and then the muscle quality related to hardness and chewiness were improved.An appropriate amount of HPM could be better used in grouper feed.
